Our overall objective is to investigate biogenic amine systems in mammalian brain as they relate to neurologic disorders such as parkinsonism. Included are studies of the anatomy of the dopaminergic, noradrenergic, and serotonergic systems. The relationship of biogenic amines and cyclic AMP systems is being studied in mammalian brain: In particular the dopamine stimulated adenylate cyclase system of the mesolimbic cortex as well as the caudate is being studied. The effects of nigrostriatal and mesolimbic denervation on these systems as well as upon behavior are being pursued. The molecular mechanisms underlying cerebellar transport of amine precursors are being investigated as is CSF clearance of metabolites. Neuromelanin in normal brain as well as in the diseased state is being studied. Finally, the histofluorescent properties of the noradrenergic and dopaminergic axons in mammalian brain are being used to study the process of regeneration and sprouting of axons in response to focal injury and deafferentation. BIBLIOGRAPHIC REFERENCES: Bowen, F.P., Karpiak, S.E., Jr., Demirjian, C. and Katzman, R.: Sprouting of Noradrenergic Nerve Terminals Subsequent to Freeze Lesions of Rabbit Cerebral Cortex. Brain Res., 83:1-14, 1975. Abramson, M.B. Katzman, R. and Choi, M.: Formation of Dopamine-Melanin by Peroxidase: Effects of 6 OH-Dopamine, Tyrosine, ATP. Trans. Amer. Soc. Neurochem., 6:198, 1975.